Immune response in deep cervical lymph nodes and spleen in the mouse after antigen deposition in different intracerebral sites

Brain interstitial and cerebrospinal fluid drainage into the lymphatics was studied by injections of 5 microliters of packed sheep red blood cells (SRBC) injected into the caudate nucleus, the occipital lobe, and the lateral ventricle of the brain in mice. The number of plaque-forming cells (PFC) was determined in the deep cervical lymph nodes, the axillary lymph nodes, and the spleen, and the number of PFC was compared with the response in the same tissues after intravenous immunization with 0.1 ml 10% SRBC. The weight of the deep cervical lymph nodes increased 3.0 times on day 3 after injection in the brain parenchyma compared with the weight of these nodes after intravenous immunization. The antigen-specific response peaked on day 5, 392 +/- 37 PFC/10(6) for IgG in the deep cervical lymph nodes after antigen deposition in the caudate nucleus, whereas only a minor peak in the antigen-specific response was obtained after intraventricular antigen deposition, 127 +/- 79 PFC x 10(6) for IgG on day 6. There were no increased PFC in any of the lymph nodes after intravenous immunization. The experiments show an antigen-specific response in the deep cervical lymph nodes after intracerebral antigen deposition, whereas antigens deposited in the lateral ventricles drain preferentially to the blood, with a high response in the spleen